Type 2 diabetes, formerly called "adult-onset diabetes", is the most common form of diabetes. About 95% of people with diabetes have type 2.

If you have type 2 diabetes, your body does not make or use insulin well. You can develop type 2 diabetes at any age, even during childhood. However, this type of diabetes occurs most often in middle-aged and older people.

Who is more likely to develop type 2 diabetes?

You are more likely to develop type 2 diabetes if you are age 45 or older, have a family history of diabetes, or are overweight. Physical inactivity, race, and certain health problems such as high blood pressure also affect your chance of developing type 2 diabetes. You are also more likely to develop type 2 diabetes if you have prediabetes or had gestational diabetes when you were pregnant.

What health problems can people with diabetes develop?

Over time, high blood glucose leads to problems such as

heart disease

stroke

kidney disease

eye problems

dental disease

nerve damage

foot problems

You can take steps to lower your chances of developing these diabetes-related health problems.

What are the symptoms of diabetes?

Symptoms of diabetes include

increased thirst and urination

increased hunger

fatigue

blurred vision

numbness or tingling in the feet or hands

sores that do not heal

unexplained weight loss

Symptoms of type 1 diabetes can start quickly, in a matter of weeks. Symptoms of type 2 diabetes often develop slowly—over the course of several years—and can be so mild that you might not even notice them. Many people with type 2 diabetes have no symptoms. Some people do not find out they have the disease until they have diabetes-related health problems, such as blurred vision or heart trouble.

Diagnosis of Type 2 Diabetes

Your health care professional can diagnose diabetes through blood tests. The blood tests show if your blood glucose, also called blood sugar, is too high.

Do not try to diagnose yourself if you think you might have diabetes. Testing equipment that you can buy over the counter, such as a blood glucose meter, cannot diagnose diabetes.

Experts recommend routine testing for type 2 diabetes if you

are age 45 or older

are between the ages of 19 and 44, are overweight or obese, and have one or more other diabetes risk factors

are a woman who had gestational diabetes1

Medicare covers the cost of diabetes tests for people with certain risk factors for diabetes. If you have different insurance, ask your insurance company if it covers diabetes tests.

Though type 2 diabetes most often develops in adults, children also can develop type 2 diabetes. Experts recommend testing children between the ages of 10 and 18 who are overweight or obese and have at least two other risk factors for developing diabetes.

low birthweight

a mother who had diabetes while pregnant with them

Tests to Diagnose Type 2 Diabetes

Health care professionals most often use the fasting plasma glucose (FPG) test or the A1C test to diagnose diabetes. In some cases, they may use a random plasma glucose (RPG) test.

Fasting plasma glucose (FPG) test

The FPG blood test measures your blood glucose level at a single point in time. For the most reliable results, it is best to have this test in the morning, after you fast for at least 8 hours. Fasting means having nothing to eat or drink except sips of water.

A1C Test

The A1C test is a blood test that provides your average levels of blood glucose over the past 3 months. Other names for the A1C test are hemoglobin A1C, HbA1C, glycated hemoglobin, and glycosylated hemoglobin test. You can eat and drink before this test.

Your health care professional will report your A1C test result as a percentage, such as an A1C of 7 percent. The higher the percentage, the higher your average blood glucose levels.

People with diabetes also use information from the A1C test to help manage their diabetes.

Random plasma glucose (RPG) test

Sometimes health care professionals use the RPG test to diagnose diabetes when diabetes symptoms are present and they do not want to wait until you have fasted. You do not need to fast overnight for the RPG test. You may have this blood test at any time.

What test results tell me if I have diabetes or prediabetes?

Each test to detect diabetes and prediabetes uses a different measurement. Usually, the same test method needs to be repeated on a second day to diagnose diabetes. Your doctor may also use a second test method to confirm that you have diabetes.

The following table helps you understand what your test numbers mean if you are not pregnant.

Diagnosis

A1C (percent)

Fasting plasma glucose (FPG)a

Oral glucose tolerance test (OGTT)ab

Random plasma glucose test (RPG)a

Normal

below 5.7

99 or below

139 or below

Prediabetes

5.6 t0 6.4

100 to 125

140 to 199

Diabetes

6.5 or above

126 or above

200 or above

200 or above

Managing Type 2 Diabetes

You should learn basic diabetes management skills. They will help prevent complications and the need for medical care. These skills include:

How to test and record your blood glucose (see blood glucose monitoring)

What to eat and when

How to take medications, if indicated

How to recognize and treat low and high blood sugar

How to handle sick days

Where to buy diabetes supplies and how to store them

It may take several months to learn the basic skills. Always continue to educate yourself about the disease and its complications, as well as how to control and live with diabetes. Over time, stay current on new research and treatment.

Testing Blood Sugar Levels

Regular self-testing of your blood sugar, called glucose monitoring, tells you how well your combination of diet, exercise, and medication are working. Tests are usually done before meals and at bedtime. More frequent testing may be needed when you are sick or under stress.

A device called a glucometer can provide an exact blood sugar reading. There are different types of devices. Usually, you prick your finger with a small needle called a lancet, which gives you a tiny drop of blood. You place the blood on a test strip, and put the strip into the device. Depending on the type of glucometer, results are available within 5 to 45 seconds.

A health care provider or diabetes educator will help set up an appropriate testing schedule for you. You will also be taught how to respond to different ranges of glucose values obtained when you self-test.

The results of the test can be used to adjust meals, activity, or medications to keep blood sugar levels in an appropriate range. Testing provides valuable information for the health care provider and identifies high and low blood sugar levels before serious problems develop.

Accurate record keeping of test results will help you and your health care provide plan how to best control your diabetes.

Diet and Weight Control for Type 2 Diabets

Meal planning includes choosing healthy foods, eating the right amount of food, and eating meals at the right time. You should work closely with your health care provider to learn how much fat, protein, and carbohydrates you need in your diet. Your specific meal plans need to be tailored to your food habits and preferences.

Managing your weight and eating a well-balanced diet are important. Some people with type 2 diabetes can stop medications after intentional weight loss, although the diabetes is still present. A registered dietitian can be helpful in determining your specific, individual dietary needs.

Regular Physical Activity

Regular exercise is important for everyone, but especially if you have diabetes. Regular exercise helps control the amount of glucose in the blood. It also helps burn excess calories and fat so you can manage your weight.

Choose an enjoyable physical activity that is appropriate for the current fitness level.

Exercise every day, and at the same time of day, if possible.

Monitor blood glucose levels at home before and after exercise.

Carry food that contains a fast-acting carbohydrate in case blood glucose levels get too low during or after exercise.

Wear a diabetes identification bracelet and carry change or a cell phone for a phone call in case of emergency.

Drink extra fluids that do not contain sugar before, during, and after exercise.

Changes in exercise intensity or duration may require modification of your diet or medication to keep blood glucose levels in an appropriate range.

Oral Medications for Diabetes

When diet and exercise do not help maintain normal or near-normal blood glucose levels, your doctor may prescribe medications for diabetes. Some of the most common types of oral medications are listed below. These are all taken by mouth.

Oral sulfonylureas (like glimepiride, glyburide, and tolazamide) trigger the pancreas to make more insulin.

Biguanides (Metformin) tell the liver to decrease its production of glucose, which increases glucose levels in the blood stream.

Alpha-glucosidase inhibitors (such as acarbose) decrease the absorption of carbohydrates from the digestive tract, thereby lowering the after-meal glucose levels.

Thiazolidinediones (such as rosiglitazone) help insulin work better at the cell site. In essence, they increase the cell's sensitivity (responsiveness) to insulin. Rosiglitazone may increase the risk of heart problems.

Meglitinides (including repaglinide and nateglinide) trigger the pancreas to make more insulin in response to how much glucose is in the blood.

If you continue to have poor blood glucose control despite lifestyle changes and taking medicines by mouth, your doctor will prescribe insulin. Insulin may also be prescribed if you have had a bad reaction to other medicines. Insulin must be injected under the skin using a syringe and cannot be taken by mouth.

Insulin preparations differ in how fast they start to work and how long they work. Your healthcare provider will determine the appropriate type of insulin to use and will tell you what time of day to use it.

More than one type may be mixed together in an injection to achieve the best control of blood glucose. Usually injections are needed one to four times a day. Your doctor or diabetes educator will show you how to give yourself an injection.

Diabetic Foot Care

A routine of diabetic foot care should be followed by those with diabetes. Diabetes can cause damage to nerves, which means you may not feel an injury to the foot until a large sore or infection develops. Diabetes can also damage blood vessels, which makes it harder for the body to fight infection.

Continuing Diabetes Care

A person with type 2 diabetes should have a visit with a diabetes care provider every 3 months. A complete examination includes:

Glycosylated hemoglobin A1c (Hb A1c) is a 3-month average of your blood glucose level. This test measures how much glucose has been sticking to red blood cells and other cells. A high HbA1c is an indicator of risk for long-term complications. The goal is to maintain a HbA1c level of less than 7 to prevent diabetic complications.

Blood pressure check

Foot and skin examination

Ophthalmoscopy examination

Neurological examination

The following evaluations should be done at least once a year:

Random microalbumin (urine test for protein)

BUN and serum creatinine

Serum cholesterol, HDL, and triglycerides

ECG

Dilated retinal exam

The Outlook for Someone with Type 2 Diabetes.

The risk of long-term complications from diabetes can be reduced. If you control your blood glucose and blood pressure, you can reduce your risk of death, stroke, heart failure, and other complications. Reduction of HbA1c by even 1% can decrease your risk for complications by 25%.

Long-term complications of diabetes include:

Diabetic retinopathy (eye disease)

Diabetic nephropathy (kidney disease)

Diabetic neuropathy (nerve damage)

Peripheral vascular disease (damage to blood vessels/circulation)

High cholesterol, high blood pressure, atherosclerosis, and coronary artery disease

Emergency complications include diabetic coma.

Seeking Medical Help

Call your health care provider immediately if you have:

Trembling

Weakness

Drowsiness

Headache

Confusion

Dizziness

Double vision

Lack of coordination

These symptoms can rapidly progress to emergency conditions (such as convulsions, unconsciousness, or hypoglycemic coma).

Prevention of Type 2 Diabetes

Everyone over 45 should have blood glucose checked at least every 3 years. Regular testing of random blood glucose should begin at a younger age and be performed more often if you are at particular risk for diabetes.

Maintain a healthy body weight and keep an active lifestyle to help prevent the onset of type 2 diabetes.

Reference: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Last updated February 7, 2017

aGlucose values are in milligrams per deciliter, or mg/dL.

bAt 2 hours after drinking 75 grams of glucose. To diagnose gestational diabetes, health care professionals give more glucose to drink and use different numbers as cutoffs.

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